Descripción de una nueva especie de bagre marino fósil (Teleostei, Siluriformes, Ariidae) del Mioceno de la provincia de Río Negro, Argentina

BOGAN, SERGIO; AGNOLIN, FEDERICO

PAPéIS AVULSOS DE ZOOLOGIA.

Universidade de Sao Paulo

Año: 2011 p. 373 - 382

0031-1049

Two fossil crania referable to the siluriform fish family Ariidae are described. The specimenscome from the Early Late Miocene-Lower Middle Miocene Saladar Member of the Gran Bajodel Gualicho Formation, located at Salinas del Gualicho, Río Negro province, Argentina. Thematerials are referred to a new species of the recent genus Genidens. The new taxon is distinguishedfrom remaining living species in having a very short, broadened and rounded supraoccipitalprocess, subrounded extrascapular and wide mesethmoid with a median notch, flatfrontals, and straight lateral margins of the sphenotics. Genidens ancestralis sp. nov. representsthe oldest (and only known) fossil record for the genus, and constitutes a relatively small-sizedspecies, very similar in general traits to living forms of Genidens.